Energy

5:21 am

Wed August 14, 2013

Complex Networks Make Up U.S. Power Grid

And whether it's worth paying to avoid all blackouts is a theme that has been on the mind of Steven Weissman, he's a professor of Electricity Law at the University of California, Berkeley. We reached him on this blackout anniversary to learn about how the nation's energy system is structured. Weissman says the grid is really made up of several complex networks.

STEVEN WEISSMAN: The lower 48 states really are divided into three grids, the eastern inner connection, that goes all the way up to basically the Rocky Mountains. Then you have the western inner connection which covers just about everything on the other side of the Rockies and then you have Texas, which operates its own grid.

GREENE: Why three grids and not seven or not one?

WEISSMAN: Well, you know, the grids actually grew organically. When we started to have companies providing power in the United States, it was really on more of a community level. And over the course of time, it became more efficient to develop much larger power plants. But because of the fact that in the United States we use power that arrives in what's referred to as alternating current, there's a cycle to it.

The power actually flows back and forth in the wires and every power source within a particular inner connection has to be synchronized. Think, for instance, about a giant game of jump rope on a playground. You have one large jump rope which is being twirled around and people keep adding themselves to the jumping and everybody who jumps in has to time themselves just right and be able to jump when everybody else is jumping.

Well, if somebody messes up or gets the timing wrong, then they're probably going to snaggle up in the ropes and everybody's gonna come to a stop, if not fall down.

GREENE: And would we be better off to have lots more smaller grids and that might help us avoid, you know, a catastrophic blackout like we saw a decade ago?

WEISSMAN: Well, there are debates that go in both directions. From a reliability standpoint, certainly having a smaller unit makes it easier to keep everything coordinated. However, the answer to your question really has to do with what your vision is for the way we're going to manage our energy systems in the United States.

Traditionally, we had this type of integrated utility company that owned and operated everything from generation down to the meter, but in the last couple of decades, there's been a big push to introduce more competition into the grid. The more you want to rely on competitive energy sources, the more you want to make the grid open and wide and available to everybody so the competitors can jump in when they've got the product to sell.

GREENE: One of the factors that contributed to the blackout back in the summer of 2003 was the huge demand for energy. I mean, it was hot. Everyone was using their air conditioners who had them. Are we any more efficient today compared to 10 years ago?

WEISSMAN: Well, we are getting better at each one of our types of uses of energy. We have more efficient appliances. Refrigerators keep getting better. Air conditioners do get better. But we also keep increasing the number of gadgets we want to use and so overall, demand keeps going up.

GREENE: Can you tell people in places like New York City and other communities that suffered through the blackout in 2003 that we're less vulnerable today than we were then?

WEISSMAN: Oh, no. There's no way to come up with a precise level of assurance. There's also really a question of how secure, how reliable we want to make the system because everything, of course, comes at a cost. Take the blackout in 2003. There had been one other blackout of a similar magnitude in the east and that had been 38 years earlier.

From one perspective, there should be zero tolerance for the kind of outage that's going to create physical and economic inconvenience for people. On the other hand, one major inconvenient episode every 38 or 40 years may not be all that bad. So the question is how much do you want to spend? What do you want to sacrifice in order to get to a higher level of reliability?

GREENE: Professor, thanks so much for talking to us about this.

WEISSMAN: You're welcome.

GREENE: Steven Weissman is director of the energy program at the Center for Law, Energy and the Environment at the University of California Berkley. Transcript provided by NPR, Copyright NPR.